#include<bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef double db;
const db r=0.57721,eps=1e-6;
LL n,m;
db ans;
int main()
{
	scanf("%lld%lld",&n,&m);
	if(n<=1e8)
		for(int i=1;i<=n;++i)ans+=1.0/i;
	else ans=log((db)(n+1))+r;
	ans/=2.0;ans*=(db)m;
	printf("%d\n",(int)(ans-eps));
	return 0;
}
